Showing papers by "Martin Luther University of Halle-Wittenberg published in 1993"
TL;DR: The genetic and molecular data suggest that the proteins of E(var)3-93D are generally involved in establishing and/or maintaining an open chromatin conformation.
Abstract: In Drosophila modifying mutations of position-effect variegation have been successfully used to genetically dissect chromatin components. The enhancer of position-effect variegation E(var)3-93D [formerly E-var(3)3] encodes proteins containing a domain common to the transcriptional regulators tramtrack and the products of the Broad complex. It interacts with a number of chromatin genes that suppress position-effect variegation. Mutations in E(var)3-93D exhibit an imprinting-like effect on the Y chromosome. This effect is transmitted paternally over several generations. Homeotic transformations in E(var)3-93D mutants indicate an involvement of the gene products in regulation of homeotic gene complexes. An antiserum raised against E(var)3-93D protein detects this chromosomal protein in a large subset of sites in polytene chromosomes. Our genetic and molecular data suggest that the proteins of E(var)3-93D are generally involved in establishing and/or maintaining an open chromatin conformation.
182 citations
TL;DR: In this paper, the crystallization behavior of Ni doped co-sputtered amorphous silicon thin films (MSP a-Si(Ni)) is investigated by means of NIR-VIS-UV transmission spectroscopy and STEM.
172 citations
TL;DR: It was shown that in all three years a higher number of grains per ear was accompanied by a lower grain weight and depending on the climatic conditions in a particular year, the increase in grain number was sufficient to compensate for the reduction in grain size and resulted in higher yields.
Abstract: Under field conditions in Germany over three growing seasons the pleiotropic effects on yield and its components of four sets of near isogenic lines carrying the GA insensitive dwarfing alleles Rht1, Rht2, Rht3, Rht1+2, Rht2+3 or rht (tall) in four different genetical backgrounds were examined together with 24 single chromosome recombinant lines segregating for the GA sensitive dwarfing gene Rht8 and the gene for day-length insensitivity Ppd1 in a ‘Cappelle-Desprez’ background. For the GA insensitive semi-dwarfs it was shown that in all three years a higher number of grains per ear was accompanied by a lower grain weight. Depending on the climatic conditions in a particular year, the increase in grain number was sufficient to compensate for the reduction in grain size and resulted in higher yields. For the Ppd1 allele yield advantages were found for wheats grown under environmental conditions of middle Europe.
132 citations
TL;DR: It is demonstrated that oligopeptides with sequences analogous to the N‐terminal part of human IL‐1β, IL‐2, TNF‐β and murine IL‐6 were hydrolyzed by purified DP IV and aminopeptidase N (AP‐N).
124 citations
TL;DR: For their helpful comments and criticism the authors of this article as mentioned in this paper thank in particular Jospeh Grieco, Isabelle Grunberg, Helga Haftendorn, Ingo Heinrich, Otto Keck, Robert Keohane, Peter Mayer, Harald Muller, InGO Peters, Glenn Snyder, Christian Tuschhoff, Stephen Van Evera, Celeste Wallander, Kenneth Waltz, Richard Weitz and Michael Zurn.
Abstract: An earlier version of this article was presented at the Annual Convention of the International Studies Association, Atlanta, 31 March–4 April 1992. For their helpful comments and criticism the authors thank in particular Jospeh Grieco, Isabelle Grunberg, Helga Haftendorn, Ingo Heinrich, Otto Keck, Robert Keohane, Peter Mayer, Harald Muller, Ingo Peters, Glenn Snyder, Christian Tuschhoff, Stephen Van Evera, Celeste Wallander, Kenneth Waltz, Richard Weitz, and Michael Zurn. The authors also acknowledge the financial support of the Deutsche Forschungsgemeinschaft and the Volkswagenstiftung.
119 citations
TL;DR: The data raise the possibility, that Dp 71 and/or Dp 116, the C-terminal translational products of dystrophin, may be causally involved in cases of mental retardation that are associated with DMD.
Abstract: Duchenne and Becker muscular dystrophies (DMD/BMD) are caused by mutations in the human dystrophin gene. About two-thirds of DMD/BMD patients exhibit gross rearrangements in the gene whereas the mutations in the remaining one third are thought to be point mutations or minor structural lesions. By means of various progressive PCR-based techniques hitherto a number of point mutations has been described that in most cases should cause premature translational termination. These data indicate a particular functional importance for the C-terminal region of dystrophin and consequently for its gene products Dp 71 and Dp 116. To screen for microheterogeneities in this gene region we applied PCR-SSCP analysis to exons 60-79 of twenty-six DMD/BMD patients without detectable deletions. The study identified seven point mutations and one intron polymorphism. Six point mutations, found in DMD patients, should cause premature translational termination. One point mutation, identified in a BMD patient, results in an amino acid exchange. Five of the DMD patients bearing a point mutation are mentally retarded suggesting that a disruption of the translational reading frame in the C-terminal region is associated with this clinical finding in DMD cases. Therefore our data raise the possibility, that Dp 71 and/or Dp 116, the C-terminal translational products of dystrophin, may be causally involved in cases of mental retardation that are associated with DMD.
110 citations
TL;DR: In this paper, tris(3-chlorodimethylstannyl-propyl) chlorostannane (carrier 1), a novel tin(IV) based carrier, was incorporated into a liquid polymeric membrane and its potentiometric properties were examined.
97 citations
TL;DR: The apparent existence of only completely edited transcripts in etioplasts and chloroplasts, indicates that light-induced processes are not acting as determinants in eliciting the editing process, and suggests that editing may, therefore, function as a regulatory device in lastid gene expression.
Abstract: The psbE operon of spinach chloroplasts, which includes the genes psbE, psbF, psbL and psbJ, encodes two RNA editing sites. One site corresponds to the initiation codon of the psbL transcript, as has been described earlier for the homologous transcript from tobacco, while at a second editing site, newly reported here, an internal phenylalanine codon of the psbF transcript is restored. Both these sites were investigated with respect to the extent of editing in spinach plastids at various developmental stages. The apparent existence of only completely edited transcripts in etioplasts and chloroplasts, indicates that light-induced processes are not acting as determinants in eliciting the editing process. Reduced editing is, however, observed in the psbF and psbL transcript from seeds and roots. This finding suggests that the RNA editing process is differentially down-regulated in leucoplasts and proplastids and that editing may, therefore, function as a regulatory device in lastid gene expression.
93 citations
TL;DR: In this paper, the implications of the comprehensive income tax for the accumulation of human and physical capital and for the overall productivity level of the economy are analyzed. But, the tax has an adverse impact on human capital accumulation and lowers productivity.
93 citations
TL;DR: The microfilamental cytoskeleton exhibited a loss of polarity in embryogenic cells but cytochalasin treatment revealed that microfilaments do not influence embryogenesis and microtubules clearly exhibited new arrangements.
79 citations
TL;DR: Patients with a self-induced disorder present a difficult management problem and it should be implied that the patient's activities are known but regarded with understanding and sympathy.
Abstract: often seen in dermatitis artefacta and may result in amputation of limbsl2 or loss of breasts or eyes. Thomas reported a patient who was finally diagnosed after}3 operations for "gangrene" by which time she had lost her entire upper extremity. Patients with a self-induced disorder present a difficult management problem. Direct confrontation should be avoided. However, ifpossible, itshould be implied that the patient's activities are known but regarded with understanding and sympathy. Psychiatric referral may be necessary. Little is known about the outcome of patients with dermatitis artefacta. In one study 33 patients were observed for 22 years. Thirtypercent continued to produce lesions 10 years after the diagnosis was made. Recovery tended to occur when the patient's life circumstances changed rather than as a result of the treatment.
TL;DR: The data support the hypothesis that DP IV, possibly in conjunction with other peptidase, is involved in the regulation of activation and proliferation of T lymphocytes.
TL;DR: In this article, the authors contribute to the determination of the heat transport properties of thin Al2O3 films, which have been generated by anodic oxidation, by using a steady state method.
TL;DR: The data indicate that a site in PSII is the origin of radical formation involved in photoinhibition and that H2O2 is an important precursor in the formation of hydroxyl-radicals in Euglena gracilis thylakoids.
Abstract: Photoinhibition of isolated Euglena gracilis thylakoids was characterised by a drastic decline in PSII photochemistry, chlorophyll-a fluorescence and an enhanced degradation of the 32-kDa protein. The process of protein degradation, as shown by studies of [14C] atrazine binding, was clearly slower than the other events. The activity of PSI was not affected. Decrease of electron-transport activity and loss of herbicide binding were prevented in the presence of various antioxidants and enzymes which protect against free radicals; however, the protection was not total. The strongest effect was observed by addition of dimethylsulfoxide, a potent hydroxyl-radical (OH*) quencher. Furthermore, combinations of various protective substances were even more effective in reducing photoinhibition. Different reactive oxygen species, including H2O2, superoxide radicals and OH* radicals were obviously involved in photoinhibition. These results were confirmed by the addition of potential OH*-radical-generating substances. Simultaneous enhancement of OH*-radical formation and photoinhibitory damage were observed in these cases. The involvement of this highly toxic species could be shown directly by a colorimetric test, thus enabling its light-mediated formation during photoinhibition to be quantified for the first time. In all, the data indicate that a site in PSII is the origin of radical formation involved in photoinhibition and that H2O2 is an important precursor in the formation of hydroxyl-radicals.
TL;DR: Many of the enhancer mutations display paternal effects consistent with the hypothesis that some of these mutations can induce genomic imprinting, and are found in the Drosophila genome as frequently as suppressor genes.
Abstract: P transposon induced modifier mutations of position-effect variegation (PEV) were isolated with the help of hybrid dysgenic crosses (pi 2 strain) and after transposition of the mutator elements pUChsneory+ and P[lArB]. Enhancer mutations were found with a ten times higher frequency than suppressors. The 19 pUChsneory(+)- and 15 P[lArB]-induced enhancer mutations can be used for cloning of genomic sequences at the insertion sites of the mutator elements via plasmid rescue. Together with a large sample of X-ray-induced (48) and spontaneous (93) enhancer mutations a basic genetic analysis of this group of modifier genes was performed. On the basis of complementation and mapping data we estimate the number of enhancer genes at about 30 in the third chromosome and between 50 and 60 for the whole autosome complement. Therefore, enhancer of PEV loci are found in the Drosophila genome as frequently as suppressor genes. Many of the enhancer mutations display paternal effects consistent with the hypothesis that some of these mutations can induce genomic imprinting. First studies on the developmentally regulated gene expression of PEV enhancer genes were performed by beta-galactosidase staining in P[lArB] induced mutations.
TL;DR: An enhanced local renin-angiotensin system in distensible coronary and systemic arteries seems to contribute to a reduced releasability of endothelium-derived relaxing factor, probably by reducing bradykinin availability.
Abstract: For more than a decade, the inhibition of the renin-angiotensin system in heart failure has been regarded as pure vasodilator therapy. Consequently, the role of the renin-angiotensin system has been seen as contributing to hemodynamic overload by vascoconstriction and volume retention. Meanwhile, clinical experience was indicated that important additional aspects of ACE-inhibition in heart failure are attenuation of the enhanced neuroendocrine activity and reversal or prevention of inappropriate trophic reactions of the overloaded myocardium. In overloaded hearts there is enhanced intracardiac formation of angiotensin due to enhanced expression of angiotensinogen and ACE, and due to accumulation of circulating, nephrogenic active renin. In human hearts, a mast-cell-derived chymase, which is not blocked by ACE-inhibition, contributes to intracardiac angiotensin formation. The enhanced intracardiac angiotensin-II formation in overloaded hearts is involved in coronary constriction, impairment of diastolic relaxation, myocyte enlargement and interstitial fibrosis, which aggravate the diastolic impairment. The major problem in overloaded, hypertrophied cardiocytes is the dedifferentiation with instabilization of Ca++-homeostasis due to an altered program of gene expression. Dedifferentiated cardiocytes have a reduced expression of sarcoplasmic reticulum Ca++-ATPase and an enhanced expression of the sarcolemmal Na+/Ca++-exchanger, resulting in an attenuation of active diastole (Ca++-reaccumulation into the sarcoplasmic reticulum), a depressed force-frequency relation, and an enhanced susceptibility for fatal arrhythmias. Furthermore, an enhanced local renin-angiotensin system in distensible coronary and systemic arteries seems to contribute to a reduced releasability of endothelium-derived relaxing factor, probably by reducing bradykinin availability. This modulation of endothelial function appears to contribute to the localization and progression of atheroma development in presence of risks factors for atherosclerosis.
TL;DR: Findings suggest a role for AP N as a new activation-associated molecule of T lymphocytes in patients suffering from juvenile chronic arthritis or rheumatoid arthritis from patients with RA.
TL;DR: In this paper, an amperometric biosensor for determination of phenol and chlorophenols using Rhodococcus has been developed, which is more sensitive to phenol, especially to mono-and dichlorinated phenol than to benzoate and monochlorobenzoates.
Abstract: An amperometric biosensor for determination of phenol and chlorophenols using Rhodococcus has been developed This sensor is more sensitive to phenol and chlorophenols, especially to mono- and dichlorinated phenol, than to benzoate and monochlorobenzoates The incubation of the sensor with phenol and its chlorinated derivatives enhanced the activity of the microbial sensor for these compounds A linear relationship between the current range and the concentration of phenol, 2-, 3- and 4-chlorophenol was observed up to 20 μmol/l The detection limit for all studied substrates was 4 μmol/l The current difference was reproducible within 55% when the test solution contained 40 μmol phenol/l
TL;DR: A comparison of the range of microcrystalline (MCC) and microfine (MFC) cellulose from different manufacturers has been undertaken as mentioned in this paper, and the results clearly indicate that care must be taken in changing from one cellulose product to another in an optimized tablet formulation.
TL;DR: It is demonstrated that the enzymatic activity of CD26 is not required for its T cell activating properties, neither via TCR/CD3 nor via CD26 itself.
TL;DR: A novel class of competitive, acylating inhibitors for the proline‐specific peptidases, which combine the efficacy of aminoacyl pyrrolidides and the potential transacylating capability of diacyl hydroxyl amines, has been developed.
TL;DR: It is demonstrated that the application of oligonucleotide probes for DNA fingerprinting is a sensitive tool for genome diagnosis in cultivated beet.
Abstract: The distribution and abundance of simple repetitive sequences complementary to the synthetic oligonucleotides (GACA)4, (GATA)4, (GTG)5 and (CA)8 in the genomes of several cultivars of Beta vulgaris and in the wild beet B. vulgaris ssp. maritima were investigated. Hybridization experiments revealed that all four motifs were present, though at different abundances, in the genomes of all of the investigated beet cultivars. Considerable intraspecific variation of the resulting DNA fingerprints was observed. The extent of polymorphism depends on the oligonucleotide probe. The most informative banding patterns were obtained with the (GATA)4 probe hybridized to HinfI-, HaeIII-, or RsaI-restricted DNA, respectively. DNA fingerprinting with (GATA)4 allowed a clear differentiation of double-haploid breeding lines (DH lines). We demonstrated that the application of oligonucleotide probes for DNA fingerprinting is a sensitive tool for genome diagnosis in cultivated beet.
TL;DR: By means of a microelectrode technique it was shown that ultrasound decreases the thickness of the USL and that this reduction was much more pronounced on the side facing the ultrasound transducer than on the opposite side of the membrane.
TL;DR: In this article, a stepwise substitution on the silicon atom has been found, and the reaction rate of the cleavage of the SiY bond decreases in the order (Y ǫ) CH 2 CHCH 2 Ω(C 6 H 5 ⪢CH 2 Â CH, CHC, OCH 3 ⪚ CH 3.
TL;DR: The catA gene, coding for the catechol 1,2-dioxygenase (C12O) of the bacterial strain Arthrobacter sp.
TL;DR: The results indicate that addition of pyruvamide results in a less compact tetramer owing to structural changes in the dimers and to their displacements.
Abstract: The influence of effectors of yeast pyruvate decarboxylase, phosphate, pyruvamide, thiamin diphosphate and Mg++, on the pH-dependent equilibrium between dimers and tetramers was studied by synchrotron radiation X-ray solution scattering. Thiamin diphosphate and phosphate shift the equilibrium to higher pH values without altering the structure of the oligomers. Pyruvamide, a substrate analogue activator, induces a significant change in the structure of the tetramer. By eliminating radiation damage by addition of dithioerythrol to the buffers, the scattering curves could be measured accurately over a large angular range. They were expanded in terms of spherical harmonics to obtain the shapes of the dimers and tetramers with higher resolution than was hitherto possible. This also allowed us to position the dimers, which are centrosymmetric at low resolution, in the tetramers which have 222 symmetry. The results indicate that addition of pyruvamide results in a less compact tetramer owing to structural changes in the dimers and to their displacements.
TL;DR: The analytical method described here allows the quantitative evaluation of urea in absolute values over the whole thickness of the horny layer in a defined area of 2.5 cm2 and was selected using the following die critera: detection limit, sensitivity, specifity, cost and.
Abstract: Urea, as a final product of protein metabolism, is a physiological substance in the human organism. The elimination of urea in humans amounts to 30 g per day; the amount in urine is of the order of 2% and in the blood 250 mg per ml. The urea content of human skin is about 1%. Urea, as one of the natural moisturizing factors, influences the capacity of the horny layer to bind water and it also has keratoplastic, penetration-promoting, antimicrobial and antipruritic properties. Therefore, the observation that pathological skin alternations are accompanied by alterations in the content of urea is not unexpected. This has been studied and confirmed previously by several investigators using various analytical methods. Schwarz determined urea in aqueous extracts of scrapings from the horny layer of healthy volunteers and of patients with atopic dermatitis or psoriasis using thin layer chromatography followed by detection with Ehrlich's reagent [6] and, in a separate study, using an amino acid analyser [7]. For the investigation of urea content in aged skin Kfigelgen and Schwarz [5] also used an amino acid analyser. The amount of urea in callus was determined by Jacobi [3] using urease [1]. The procedure applying the amino acid analyser permits a determination of urea values only related to the part of amino acids. A disadvantage of all the methods previously described is that, in using scrapings from the horny layer, only the very superficial parts of the stratum corneum are considered. The analytical method described here allows the quantitative evaluation of urea in absolute values over the whole thickness of the horny layer in a defined area of 2.5 cm 2. The method was selected using the following die critera: detection limit, sensitivity, specifity, cost and
TL;DR: A gene encoding a protein homologous to the translation initiation factor eIF-4A in mouse has been identified in Drosophila melanogaster and is located on chromosome arm 2L at 26A7-9.
Abstract: A gene encoding a protein homologous to the translation initiation factor eIF-4A in mouse has been identified in Drosophila melanogaster. The predicted amino acid sequence shows 73% identity with the mouse gene and 67% identity with a homologous protein from yeast. The single-copy Drosophila gene is located on chromosome arm 2L at 26A7-9. Several recessive lethal mutations have been isolated and genetically characterized. Northern blot hybridization shows two abundant transcripts of 1.75 kb and 1.9 kb throughout all developmental stages. Both transcripts are maternally provided to the oocyte.
TL;DR: By adding salts (sodium chloride, ammonium sulfate), it is possible to induce phase separation in membrane-protein solubilisates containing Triton X-100 or Nonidet P-40 at temperatures between 0 and 20 degrees C.